Reviewed by USGSIndonesia40y ago
M4.8 earthquake 117 km NW of Tobelo, Indonesia
Wednesday, April 15, 1987, 05:51:32 UTC · 2.360°N, 127.155°E
A magnitude 4.8 earthquake struck 117 km NW of Tobelo, Indonesia on Wednesday, April 15, 1987, 05:51:32 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.1 on April 14, 1987.
- Magnitude
- 4.8
- Light · mb
- Depth
- 33 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
3 km
from the nearest mapped plate boundary, between the Sunda and Birds Head plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
33 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 50 km
USGS lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.1 on April 16, 1987. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 896 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8161 km SE of Sarangani, PhilippinesApril 1, 1936 · 229 km N of this epicenter
- 7.790 km NE of Tobelo, IndonesiaSeptember 8, 1966 · 148 km E of this epicenter
- 7.7148 km SE of Tondano, IndonesiaMay 14, 1932 · 261 km SW of this epicenter
- 7.7121 km E of Bitung, IndonesiaAugust 10, 1968 · 143 km SW of this epicenter
- 7.6101 km SE of Sarangani, PhilippinesDecember 16, 1910 · 286 km NW of this epicenter
- 7.6223 km ESE of Sarangani, PhilippinesJanuary 30, 1969 · 257 km N of this epicenter
- 7.564 km NNW of Ternate, IndonesiaJune 25, 1907 · 114 km S of this epicenter
- 7.5146 km NW of Ternate, IndonesiaAugust 14, 1986 · 95 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 20 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,965 recorded deaths. The most severe:
- 1856
Sangihe Pulau (Volcanic)
2 Mar 1856 · 234 km away
2,806 deathsSevere damage ($5–24M)tsunami
- 1845M7.0
N Sulawesi: Menado, Tikala, Tomohon
8 Feb 1845 · 274 km away · intensity IX
118 deathsModerate damage ($1–5M)tsunami
- 1855
Maluku: Ternate Island
14 Jul 1855 · 174 km away · intensity IX
34 deathsModerate damage ($1–5M)
- 1932M7.7
Sulawesi: Kakas,Langowan,Poso,Tondano
14 May 1932 · 261 km away · intensity VII
7 deathsSevere damage ($5–24M)tsunami
- 1858M7.3
N. Moluccas Islands
13 Dec 1858 · 198 km away
Severe damage ($5–24M)tsunami
- 1889M8.0
N. Moluccas Islands
6 Sep 1889 · 182 km away
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.